The campaigns rushed to move staff and volunteers, close offices and cancel events in the path of the storm. And as many Floridians heeded calls to evacuate, both candidates began the delicate and difficult task of pursuing votes during a crisis.

"Even if you want to do politics, no one is there to listen," said Steve Schale, a Democratic consultant who directed or advised Barack Obama's campaigns in Florida in 2008 and 2012.

Clinton's campaign asked the state for more time to register voters — a request Florida Gov. Rick Scott rejected — and the Trump team pulled its negative TV ads.

"It looks like it's a big one and it's going to be a bad one," said Trump at a town hall in New Hampshire. "Please know that we are praying for you and everyone in the path: You've got to take care of yourself, you've got to get out of the area, you've got to listen."

In the storm's path is Mar-a-Lago, Trump's Palm Beach resort, the AP notes.

Back in Georgia, Secretary of State Brian Kemp urged residents in Matthew's path to take advantage of the state's online and mobile voter access points, since the storm could delay mail service to some Georgia counties.